Scientists create 'no-tears' onion

Scientists have created an onion that won't cause you to cry using Australian-developed biotechnology to switch off the gene behind the enzyme that brings on the waterworks.

Using gene-silencing technology, the New Zealand-based research institute Crop and Food pioneered the breakthrough and hopes could lead to a prototype onion hitting the market in a decade's time.

Colin Eady, the institute's senior scientist, told the Herald Sun that the project started in 2002 after Japanese scientists found the gene responsible for producing the agent behind the tears.

"We previously thought the tearing agent was produced spontaneously by cutting onions, but they proved it was controlled by an enzyme," he said.

"Here in New Zealand we had the ability to insert DNA into onions, using gene-silencing technology developed by Australian scientists.

"The technology creates a sequence that switches off the tear-inducing gene in the onion so it doesn't produce the enzyme. So when you slice the vegetable, it doesn't produce tears."

Mr Eady said that by stopping sulphur compounds from being converted to the tearing agent and redirecting them into compounds responsible for flavour and health, the process could even improve the taste of the onion.

"We anticipate that the health and flavour profiles will actually be enhanced by what we've done,'' he said.

"What we're hoping is that we'll essentially have a lot of the nice, sweet aromas associated with onions without that associated bitter, pungent, tear-producing factor.''

The discovery has caused concern overseas, following an international symposium in the Netherlands and after the trade journal Onion World featured Eady's work on the front cover of its December issue last year.

...oh yes

Mr Eady, who has developed several model onion plants at the institute, said despite the excitement about the prospect of a "no tears" onion in every home, it would be 10 to 15 years before this was a reality. ®